The primary goal of this research is to advance understanding of the representations underlying infants' task-dependent behavior with hidden objects. Infants can appear precocious or limited in almost any ability depending on the task administered to them. For example, infants as young as 3.5 months show an apparent sensitivity to the continued existence of hidden objects in visual habituation studies, yet infants fail to manually search for objects hidden by occluders through around 9 months. And, infants as young as 5 months reach for objects in the dark. Such task-dependent behaviors can be interpreted in many ways, resulting in numerous contradictory claims about what infants know, from very young infants possessing a concept of object permanence to much older infants representing nothing about hidden objects. This project addresses this debate by focusing on the following questions: 1. How do inherent and incidental task factors contribute to infants' task- dependent behavior? 2. How do distinct types of representations contribute to infants' task- dependent behavior? 3. How do graded representations contribute to infants' task-dependent behavior? The primary methodology for this project is the detailed analysis of infants' response to objects that are presented and then hidden from view, across three paradigms: visual habituation, reaching in the dark, and searching under visible occluders. Findings from these studies will illuminate the influence of a variety of factors in the representations infants use across different tasks. In this way, the proposed work provides a coherent program for advancing our understanding of the factors contributing to infants' task-dependent behavior--an essential step toward characterizing the nature of infants' representations, and in turn informing theory and its application to both typical and special populations.